This invention relates to waveform generators and, more particularly, to biological waveform simulator devices for testing the operability of medical electronic equipment.
There is an increasing trend towards using more electronic equipment in the medical profession. Typical of such equipment includes the use of blood pressure monitors, electrocardiogram machines, and vectorcardiogram machines. It is obviously of paramount importance that these devices operate properly at all times. For many years, malfunctions of these devices were detected primarily by observing the operation of the machine on a live patient. The time required to either fix the malfunction or replace the machine is obviously detrimental in emergency situations. Moreover, it was difficult to detect whether the machine, while appearing to perform normally, was actually calibrated properly and generating a correct reading.
To correct many of these problems noted above, simulator devices have been utilized to simulate biological waveforms that can be used to test the operability of blood pressure monitors and electrocardiogram machines. Examples of these devices are more fully disclosed in U.S. Ser. No. 882,357, entitled "Complex Analog Signal Generator", filed Mar. 1, 1978, (now U.S. Pat. No. 4,204,261); and U.S. Ser. No. 938,430, entitled "Electrocardiographic Blood Pressure Waveform Simulator Device", filed Aug. 31, 1978, (now U.S. Pat. No. 4,205,386). These simulators, while having provided extremely satisfactory results, are not capable of testing the operability of a vectorcardiogram machine. Vectorcardiogram machines are somewhat complicated devices in which electrocardiograms are taken along three axes (X, Y, and Z) at right angles to one another, with any two of these ECG's being displayed as a vector on an X-Y oscilloscope. The present invention is directed to fulfilling a long felt need for a reliable, yet relatively inexpensive, means for testing the operability of vectorcardiogram machines before being utilized on a live patient.